Method of constructing a rotor for a rotary regenerative heat exchanger

ABSTRACT

The method of manufacturing a rotor for a rotary regenerative heat exchanger that has a horizontal rotor shaft with an annular mass of heat absorbent element disposed in containers arranged concentrically therearound. In order to prevent the inclusion of uneven stresses therein that would effect warping of the rotor and possible cracking and break-down of the constituent welds, the several independent parts thereof are joined together at their edges by a system of expansible joints. Other connections of the rotor are pivotal, and only after assembly of the rotor is complete and the rotor parts have adjusted to one another are the expansible connections uniformly tightened so that the rotor is made into an integral body.

United States Patent Kurschner et al.

METHOD OF CONSTRUCTING A ROTOR FOR A ROTARY REGENERATIVE HEAT EXCHANGER Inventors: Hermann E. Kurschner; Harlan E.

Finnemore, both of Wellsville, N.Y.

Assignee: The Air Preheater C0., lnc.,

Wellsville, N.Y.

Filed: Jan. 17, 1974 Appl. No.: 435,393

U.S. c1 29/1575 R, 165/9, 165/10 1111.0 B23p 15/26 Field 01 Search 29/1573 D, 157.3 R;

References Cited UNITED STATES PATENTS Finnemore 165/9 3,789,916 2/1974 Lindahl 165/10 X Primary ExaminerC. W. Lanham Assistant ExaminerD. C. Reiley, Ill

Attorney, Agent, or Firm-Wayne H. Lang [57] ABSTRACT The method of manufacturing a rotor for a rotary regenerative heat exchanger that has a horizontal rotor shaft with an annular mass of heat absorbent element disposed in containers arranged concentrically therearound. In order to prevent the inclusion of uneven stresses therein that would effect warping of the rotor and possible cracking and break-down of the constituent welds, the several independent parts thereof are joined together at their edges by a system of expansible joints. Other connections of the rotor are pivotal, and only after assembly of the rotor is complete and the rotor parts have adjusted to one another are the expansible connections uniformly tightened so that the rotor is made into an integral body.

5 Claims, 2 Drawing Figures METHOD OF CONSTRUCTING A ROTOR FOR A ROTARY REGENERATIVE HEAT EXCHANGER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rotary regenerative heat exchangers and has particular relation to heat exchangers of this general type that are assembled around a rotary shaft that is disposed about a horizontal axis. More importantly, a heat exchanger whereby a rotor for the heat exchanger is comprised of independent parts that are pivotally held so the independent parts thereof are free to expand and contract without warping or breaking the connection therebetween.

2. Description of Prior Art Conventional rotary regenerative heat exchangers are comprised of individual parts that are first assembled and then connected together by a system of welded joints in the manner defined by US. Pat. No. 3,267,562 of Chiang. A heat exchanger constructed according to the above design appears rugged and strong, but when subjected to repeated temperature variations as may attend normal service operations, a differential of expansion occurs and a substantial stress is concentrated in the welded joints between the several parts whereby cracking and breakage occurs to such an extent that it may materially reduce the life expectancy of the heat exchanger or else subject the unit to complete breakage and failure.

In US. Pat. No. 3,710,850 of Kursch'ner, et al, a rotary regenerative heat exchanger is disclosed wherein independent but similar baskets of heat absorbent element are pivotally attached to a central rotor post. l-Iere great difficulty is experienced in evenly attaching the similar baskets of element to the central rotor post so that a rotor so constructed is uniformly stressed and completely round. Moreover, the several baskets thereof are variously spaced from the rotor post and from one another so they provide an outer sealing surface that is rieither round nor continuous and thus promotes excess leakage.

SUMMARY OF THE INVENTION In accordance with the present invention I therefor provide a method of constructing a rotary regenerative heat exchanger that is substantially round, and the outer surface thereof provides a continuously arcuate sealing surface, and each individual component thereof is attached pivotally so there is a complete absence in the rotor of the heat exchanger of uneven stresses. Such uneven stresses promote distortion, warping and a differential expansion that leads to poor sealing conditions, cracking or breaking of the welded joints between the several independent parts, and the eventual breakdown of the entire rotor structure.

BRIEF DESCRIPTION OF THE DRAWING A more complete understanding of my invention may be realized by referring to the following description which may be viewed in conjunction with the accompanying drawing in which:

FIG. 1 is a perspective view of a rotary regenerative heat exchanger built according to the present invention, and

FIG. 2 is a perspective view of a regenerative heat exchanger in the preliminary steps of assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT The arrangement of the drawing shows a rotary regenerative heat exchanger with a horizontally disposed rotor post 12 that is rotatably mounted on a pair of spaced-apart support bearings 14 and rotated about its axis by means such as a drive motor 15 that is connected through suitable reduction gearing 16 to the rotor post 12. A mass of heat absorbent material 18 contained in the independent sector-shaped baskets 22 is adapted to absorb heat from the hot fluid and then give it up to the cooler fluid flowing therethrough.

The baskets 22 are open at opposite ends thereof to permit the flow of fluid therethrough and are secured at a pivotal coupling 26 that permits limited relative movement between adjacent baskets 22 and between the baskets and the rotor post 12.

The rotor 28 is surrounded by a rotor housing 30 having end plates positioned opposite ends of the rotor with openings 36, 38, 42 and 44 for the inlet and outlet of the heating fluid and the fluid to be heated.

To preclude the leakage of fluid through the space between the rotor and the rotor housing, sealing means 45 are provided at the end edges of the rotor to bridge the space between the rotor and the rotor housing in accordance with standard practice.

Pivotal couplings 26 are used to support each basket 22 outward from the rotor post 12 and simultaneously permit a limited amount of relative movement therebetween. The radial outer ends of the baskets are bolted together at 54 that provide an integral rotor.

According to this invention, a rotor post 12 is therefore horizontally disposed and rotatably supported by a pair of spaced-apart support bearings 14. A first sector-shaped basket of element 22 is moved into position adjacent the rotor post 12 by suitable hoisting equipment and pivotally attached thereto by a single pivoted joint 26. After a basket of element has been attached to the rotor post it is allowed to depend freely therefrom so that the rotor post 12 will rotate freely in the bearings 14 because of the unbalance thereof until the basket 22 depends vertically beneath the rotor post and a state of equilibrium exists.

At this point a second element basket is raised into position adjacent the first basket and attached by a pivotal connection 26 to the rotor post 12 and loosely attached to an adjacent basket at 54.

The rotor post and attached baskets is then again permitted to rotate as required to bring the assembly into a state of equilibrium wherein the center of gravity of the attached baskets is aligned beneath the rotor post.

The additional baskets of element 22 are pivotally at tached to the rotor post 12 and loosely attached to an adjacent basket until the rotor comprises a substantially annular body that is pivotally held by the joints 24 to the rotor post. As each additional basket 22 is secured to the rotor post, the entire mass of element together with the rotor post is permitted to rotate slightly until it hangs in a condition of equilibrium.

After the rotor has been completely assembled, the rotor is rotated slowly and each loose connection between baskets of element 22 is progressively tightened as it moves past a point beneath the rotor post so that the rotor assumes an annular configuration concentric with the rotor post.

Frequently it is necessary to insert a shimming means 32 between two or more baskets to produce a continuous surface around the periphery of the rotor to provide a smooth surface that will cooperate with the sealing surface at the ends of the rotor and preclude fluid by-passing the rotor without contacting the element 22.

We claim:

1. The method of constructing a rotor for a rotary regenerative heat exchanger comprising the steps of rotatably supporting a horizontally disposed rotor post on a pair of spaced-apart support bearings, pivotally connecting a first sector-shaped element basket to the rotor post intermediate the support bearings, permitting the rotor post with attached element mass to rotate in said bearings until it attains a state of equilibrium, pivotally attaching a second sector-shaped basket of heat absorbent element to the rotor post, permitting the rotor post to rotate in said bearings until a state of equilibrium is again achieved, alternately connecting other baskets of element to said rotor and then permitting them to rotate with the rotor post to attain equilibrium until the rotor comprises an annular body, and

connecting the radial outer ends of the sector-shaped baskets to one another to comprise an integral element mass that extends concentrically about and is pivotally attached to the rotor post.

2. The method of constructing a rotor according to the method defined in claim 1 wherein each basket of heat absorbent element attached to the rotor post lies laterally adjacent a basket previously attached thereto.

3. The method of constructing a rotor according to claim 2 in which each basket of heat absorbent element is attached to alternate sides of the element previously attached thereto.

4. The method of constructing a rotor according to claim 1 including the step of inserting shimming means intermediate basket ends as required to produce a continuous annular element mass that extends around the rotor post.

5. The method of constructing a rotor according to claim 1 wherein all loose connections are uniformly tightened after the rotor assembly is complete. 

1. The method of constructing a rotor for a rotary regenerative heat exchanger comprising the steps of rotatably supporting a horizontally disposed rotor post on a pair of spaced-apart support bearings, pivotally connecting a first sector-shaped element basket to the rotor post intermediate the support bearings, permitting the rotor post with attached element mass to rotate in said bearings until it attains a state of equilibrium, pivotally attaching a second sector-shaped basket of heat absorbent element to the rotor post, permitting the rotor post to rotate in said bearings until a state of equilibrium is again achieved, alternately connecting other baskets of element to said rotor and then permitting them to rotate with the rotor post to attain equilibrium until the rotor comprises an annular body, and connecting the radial outer ends of the sector-shaped baskets to one another to comprise an integral element mass that extends concentrically about and is pivotally attached to the rotor post.
 2. The method of constructing a rotor according to the method defined in claim 1 wherein each basket of heat absorbent element attached to the rotor post lies laterally adjacent a basket previously attached thereto.
 3. The method of constructing a rotor according to claim 2 in which each basket of heat absorbent element is attached to alternate sides of the element previously attached thereto.
 4. The method of constructing a rotor according to claim 1 including the step of inserting shimming means intermediate basket ends as required to produce a continuous annular element mass that extends around the rotor post.
 5. The method of constructing a rotor according to claim 1 wherein all loose connections are uniformly tightened after the rotor assembly is complete. 